Weather/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby An image shows a web page on a computer screen. The face of Moby is accompanied by text. The text reads: Incredibly accurate weather forecasted by robots. A cursor clicks on the text, and another web page asks for the user's credit card information. Text on this page reads: Enter your credit card number here for the most incredibly accurate forecast ever. Tim speaks. TIM: I'm not paying you for a weather forecast. Tim is sitting at his desktop computer, looking at Moby's website. Moby stands beside him. TIM: You know there are lots of places where you can get the weather for free, right? MOBY: Beep. TIM: No. They actually use state-of-the-art satellite technology and computer models and— MOBY: Beep! TIM: Well, that's not a very nice thing to say about Al Roker. Tim's e-mail pings. He brings up his e-mail screen, and there is a message with the subject line: Question for BrainPOP. Tim clicks on the e-mail. Tim reads a typed message. TIM: Dear Tim and Moby, what is weather? Sincerely, Domenica. Tim and Moby stand in Tim's bedroom. TIM: Basically, weather is the condition of the atmosphere at a certain place and time. MOBY: Beep. TIM: Well, the weather depends on a lot of factors. First off, there's temperature. You probably all know about that. It's a measure of how hot or cold the air is, and it depends on how much energy the air receives from the sun. Temperature is measured with a device called a thermometer and is usually calculated in degrees Celsius or degrees Fahrenheit. An animation shows a thermometer with both Celsius and Fahrenheit scales on it. The thermometer's mercury rises, indicating that the air is becoming warmer. TIM: Temperature is related to another factor, humidity. Humidity is the amount of water vapor in the air. MOBY: Beep? TIM: Yep. The air around us is full of water. A detail animation shows water molecules in the air near Tim and Moby. TIM: You can't usually see it, but it evaporates from lakes, rivers, oceans, even from trees. An animation shows water evaporating into a sunny sky from a body of water and a stretch of land. TIM: There are two types of humidity. Absolute humidity is a measure of how much water vapor the air is capable of holding. The hotter the air is, the more moisture it can hold. An animation shows a cube next to a thermometer. Outlines of water molecules appear in the cube to represent absolute humidity. As the temperature rises, more water molecule outlines appear in the cube to show that hot air has a high absolute humidity. TIM: Relative humidity is a measure of how much moisture there actually is in the air. It's expressed as a percentage of the absolute humidity. Half of the water molecule outlines in the cube are filled with water to show the relative humidity is 50 percent. Text reads: 50% humidity. TIM: If the relative humidity is 100 percent, it means the air is totally saturated with water. In the humidity animation, all the water molecule outlines are filled with water. Text reads: 100% humidity. TIM: When the humidity rises, the air feels heavy, sticky, and uncomfortable. An image shows a robot sunbathing on a hot beach. The robot is sweating. MOBY: Beep! TIM: That's right. When the humidity gets near 100 percent, the air can't hold any more moisture. If the temperature falls at this point, the water vapor starts returning to its original liquid state. An animation shows water vapor becoming water droplets. TIM: It comes together in a process called condensation. The robot on the beach looks up as clouds gather overhead. TIM: When condensation happens close to the ground, it can produce mist or fog. An animation shows fog accumulating on the ground. TIM: And way high up in the atmosphere, condensation makes clouds. An animation shows clouds forming in the sky. TIM: Eventually, the water in the clouds comes back to Earth as rain, snow, or hail. The sunbathing robot is now rusting as it rains. SUNBATHING ROBOT: Beep. TIM: What next? MOBY: Beep. TIM: Oh, right. Air pressure. You might not realize it, but the air around you actually has weight. We measure air pressure with a device called a barometer. An image shows a barometer. TIM: In areas of high pressure, air slowly descends toward the earth's surface. An animation shows an area of high pressure, with air flowing downward as Tim describes. TIM: High-pressure areas are associated with clear, sunny days. The rusty robot that had been sunbathing now sits on a park bench. The sky is clear and sunny. TIM: In areas of low pressure, air rises upward into the atmosphere. An animation shows an area of low pressure, with air ascending as Tim describes. TIM: Low-pressure areas bring high humidity, clouds, and, you guessed it, rain and other precipitation. The robot on the park bench is being rained upon. ROBOT: Beep. TIM: When you look at a weather map, you'll see all the different areas of high and low pressure marked with big Hs and Ls. An animated weather map shows the eastern United States. A large letter H and a large letter L are both highlighted. Wavy lines separate the different air pressure areas. TIM: These air masses are constantly moving around. A high pressure area that's over Ohio on Wednesday might be over New York City on Thursday. Air pressure lines on the map shift to show how air masses move as Tim describes. TIM: The boundaries between these air masses are called fronts. And that's where heavy storms and other serious weather can take place. The wavy lines on the weather map are highlighted and labeled "fronts." MOBY: Beep! TIM: Anyway, an area's long-term weather patterns determine its climate. For example, areas near the equator have a warm climate, while areas near the poles have a much colder climate. Images show a hot, sunny equatorial location and a cold, icy polar location. TIM: So that's weather. Another e-mail message arrives on Tim's computer. This subject line reads: MobyWeather.com has a new subscriber. MOBY: Beep! Moby claps. TIM: Wow, whoever signed up for your site must be really desperate. Moby frowns. The sunbathing robot from earlier is at his own desktop computer. He is the one who has signed up for Moby's forecasts. ROBOT: Beep? A forecast appears on the rusty robot's computer. It includes a picture of Moby's face. Text reads: The weather in your area is Beep Beep Beep. Tomorrow's forecast, Beep, with a 30 percent chance of beep. ROBOT: Beep! The robot smashes his computer in anger and walks off. Category:BrainPOP Transcripts Category:BrainPOP Science Transcripts